Risk of Down Syndrome During Pregnancy

Frequently women ask me about the risk of having a baby with Down syndrome. As you get older, the risk of delivering a baby with Down syndrome increases, as the following statistics show:

at age 25 the risk is 1 in 1,300 births

at 30 it is 1 in 965 births

at 35 it is 1 in 365 births

at 40 it is 1 in 109 births

at 45 it is 1 in 32 births

at 49 it is 1 in 12 births

But you can look at these statistics in a more positive way: Even at age 49, you have a 92% chance of delivering a child without Down syndrome.

Down syndrome is a condition in which a baby is born with mental disabilities and often physical deformities too. A person with Down syndrome may have a sloping forehead, short, broad hands, a flat nose and low-set ears. There may also be heart problems, gastrointestinal defects or leukemia. Down syndrome is caused by an extra chromosome.

Down syndrome can be diagnosed before the baby is born. Traditionally amniocentesis has been used to diagnose the condition. Other tests that may prove useful include alpha-fetoprotein, triple screen, quad screen, chorionic villus sampling and, in some cases, ultrasound.